The gut bacteria of older women who eat plant-based diets are better at breaking down fiber into beneficial short-chain fatty acids, while those of meat-eaters are more active in breaking down proteins, reflecting how diet influences what gut microbes do.
Evidence from Studies
No evidence studies found yet.
What Would Prove This
Per GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this claim, ordered from strongest to weakest.
Whether vegetarian diets consistently associate with increased microbial carbohydrate fermentation and SCFA pathway enrichment compared to omnivorous diets across diverse populations.
A systematic review and meta-analysis of all studies using metagenomic or metatranscriptomic data to compare microbial functional pathways related to carbohydrate fermentation and protein catabolism in postmenopausal vegetarians versus omnivores, with standardized pathway annotation (KEGG/eggNOG).
Whether switching from an omnivorous to a vegetarian diet for 12 weeks increases microbial gene expression related to carbohydrate fermentation and SCFA synthesis in postmenopausal women.
A double-blind RCT of 60 postmenopausal women (60–75 years) randomized to 12 weeks of vegetarian diet (≥50g fiber/day) or omnivorous diet, with fecal metatranscriptomics at baseline and endpoint to measure changes in expression of SCFA synthesis and protein catabolism genes.
Whether long-term vegetarian diet adherence predicts increased microbial carbohydrate fermentation capacity over time in postmenopausal women.
A prospective cohort study following 250 postmenopausal women for 5 years, collecting annual fecal samples for metagenomic sequencing and dietary records, analyzing changes in microbial gene abundance for SCFA and amino acid degradation pathways.
Whether women with high fecal SCFA levels are more likely to have followed a vegetarian diet for ≥5 years than those with low SCFA levels.
A case-control study comparing 100 women with high fecal SCFA levels (top quartile) to 100 with low levels, matched for age and BMI, and assessing dietary history over the past 5 years via validated food frequency questionnaires.
Whether vegetarian diet status correlates with predicted microbial functional enrichment for carbohydrate fermentation in postmenopausal women.
A cross-sectional analysis of 200 postmenopausal women comparing vegetarian and omnivorous diets using 16S sequencing and PICRUSt2 to predict functional enrichment in carbohydrate fermentation and protein catabolism pathways.